Improvement in watch and clock keys



G. E. LOMBARD.

Watch and Clock Key.

No. 211,918. Patented Feb. 4, 1879.

N-FETERS, FHOTO-I-ITHOGRAFHER, WASHMGTOMD. O.

NITED STATES PATENT FF CHARLES E. LOMBARD, OF CAMBRIDGE, ASSIGNOB 0F ONE-HALF HIS RIGHT TO CHARLES F. BROWN, OF READING, MASSACHUSETTS.

IMPROVEMENT IN WATCH AND CLOCK KEYS.

Specification forming part of Letters Patent No. 211,918, dated February4, 1879; application filed May :24, 1878.

To all whom it may concern:

Be it known that 1, CHARLES E, LOMBARD, of Cambridge, in the county ofMiddlesex and State of Massachusetts, have invented certain Improvementsin Watch or Clock Keys, of which the following is a specification:

This invention relates to watch orclock keys in which the shank orhandle of the key is made elastic or resilient for the purpose ofpreventing breakage of the mainspring of the watch or clock when themainspring is entirely wound up,the resilient shank of the key being soconstructed that it will be unyielding, and will resist the forcerequired to wind up the mainspring until the latter is entirely woundup, and then yield if the key is additionally turned.

My invention hasfor its object to improve the construction of keys ofthe above-named class with respect to efficiency of operation andcheapness; and to this end it consists in the employment of a spiralspring as the shank of a watch or clock key, said spring being rigidlyattached to the pipe or barrel of the key, as I will now proceed todescribe.

Of the drawingsforming a part of this specification, Figure 1 representsa side view of a watch or clock key embodying my invention. Fig. 2represents a longitudinal section of the same. Fig. 3 represents a sideview of a modification.

Similar letters of reference indicate correspondin g parts.

In the drawings, a represents the pipe or barrel of a watch or clockkey, the same being provided, as usual, in its outer end,with' asqua-recavity, to fit over the winding-post of a watch or clock. The oppositeend of the pipe is formed with a shoulder, 11, the pipe being reduced toform this shoulder. 0 represents the elastic or resilient shank. whichis composed of a single wire, and is formed at one end to fit closelyon'the reduced end of the pipe at and bear against the shoulder b. Theend of the spring is rigidly secured to the pipe by soldering or in anydesired manner. I prefer to enlarge the coils or convolutions of thespring above the end which is attached to the pipe, and mill or roughenthe outer surfaces of the enlarged coils, as shown in Fig. 1. Theenlarged" milled portions enable the key to be easily turned by thethumb and finger of the operator. If desired, the outer or upper end ofthe spring 0 may be formed into a loop or handle, 0, as shown in Fig. 3.The spring is made of such strength that when the key is being turned towind a watch or clock there will be no yielding or resilience in theshank of the key until the spring is entirelywound up and comes to astop, when, in case the key is further rotated, the shank 0 will yield,and thus relieve the strain on the mainspring and its stops, and preventthe key from turning or slipping on the latter.

The chief advantages of the spiral spring are, first, its cheapness andthe ease with which it can be attached to the pipe; and, second, itsadaptability to yield in either direction, so that its function will bethe same whether the watch or clock winds to the right or to the left.The shank thus constructed is also flexible, so that it can be bent ineither direction laterally, and thus avoid contact with the opened coverof the watch in winding.

I claim as my invention- A watch or clock key composed of a pipe orbarrel and a spiral spring attached thereto, and forming a flexibleshank or handle, as and for the purpose specified.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

CHARLES E. LOMBARD.

Witnesses:

G. F. BROWN, Gno. W. PIERCE.

